Implantable endovascular, low profile intracardiac left atrial restraining devices for low energy atrial cardioversion, pacing and sensing

ABSTRACT

Disclosed are various configurations of electrodes with accompanying extensions and wires configured to be attached at or near the left atrium of a heart to allow the device to be held snug against the endocardium and out of the blood flow for low energy defibrillation of the atria in response to atrial fibrillation or other atrial arrhythmias. The portion of the lead internal to the atrium (e.g., the left atrium) is restrained against the endocardium of the left atrium by way of a restraint mechanism. In one example, the electrode is configured to attach to the atrial septum, with wires containing memory-shaped metal to keep the wires against the heart wall. In yet another example, the electrode is configured to be part of a mitral valve device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/944,540, filed Dec. 6, 2019, and titled “IMPLANTABLE ENDOVASCULAR,LOW PROFILE INTRACARDIAC LEFT ATRIAL RESTRAINING DEVICES FOR ULTRA LOWENERGY ATRIAL CARDIOVERSION”, which is hereby incorporated by reference.

BACKGROUND

Wires placed in the heart connected to pacemakers have been used in theright side of the human heart since 1957 (Earl Bakken-founder ofMedtronic). Since then millions of wires for sensing, pacing anddefibrillating the heart have extended and saved lives around the world.Despite this body of work, wires are not used on the left side of theheart. Mitral valve devices, left atrial occlusion devices, and septalocclusion devices have been placed on the left side of the heart fordecades. However, wires traditionally have not been placed on the leftside of the heart because of the risk that a thrombus collecting on awire floating free in the heart can detach. If the wire is on the rightside of the heart, and a thrombus develops and detaches, the thrombuscan only travel to the lungs, and intrinsic enzymes can be used to breakdown the clot. However, if a wire is on the left side of the heart and athrombus develops and detaches, the clot will travel into the aorta andto the brain. The brain has no intrinsic mechanism to dissolve the clot,and a stroke can occur, which can be devastating.

Defibrillating the human heart has saved many lives. Initially performedonly externally (through the skin), defibrillators are now placedinternally (endovascular and intracardiac and extracardiac) toemergently defibrillate the heart to terminate dangerous arrhythmias.Current defibrillators need relatively high energy (as measured injoules) to defibrillate the heart. These shocks are painful to thepatient and cause incredible anxiety. The energy utilized wears down thebatteries quickly, which then require replacing. Replacing thegenerators and batteries are expensive (the batteries are incorporatedinto the generators) and there is the risk of infection with generatorand battery replacement. Infections are sometimes fatal and are veryexpensive to the medical system.

Atrial fibrillation (AF), the most common human cardiac arrhythmia,causes great morbidity, mortality and cost. Although AF is present onlyin the atrial chambers of the heart today the entire heart isdefibrillated for AF because leads to the heart for defibrillationgenerally do not include leads placed in the left atrium (LA).Accordingly, it is difficult to sense the LA for the occurrence ofarrhythmias and difficult to selectively defibrillate the LA. As such,defibrillating the heart in response to AF generally requiresdefibrillating the entire heart.

SUMMARY

The embodiments described herein pertain to various configurations oflow profile electrodes and accompanying structures that hold theelectrodes and wires against the endocardium (eliminating free floatingwires) and configured to be attached at or near the left atrium of theheart to allow for low energy recording, sensing, pacing, and/ordefibrillation of the atria in response to atrial fibrillation or otheratrial arrhythmias. In addition to defibrillating the upper chambers ofthe heart, these electrodes and accompanying structures can be utilizedto sense and map normal and abnormal electrical impulses. The devicescan also be used in conjunction with leads implanted in the rightatrium, the right ventricle, the coronary sinus and leads on the outsideof the heart. In one embodiment, the electrode is configured to attachto the atrial septum, with the wire attachment that holds the wiresagainst the heart tissue. In another embodiment, the electrodeconfiguration is attached to a modified atrial septal closure device(could also be an atrial septal opening device, again with the specialattachment keeping the wires held fast against the heart wall. Inanother embodiment, the electrode is configured to be part of an atrialappendage closure device, also with the special attachment that keepsthe wire from free floating, on either the inside (endocardial surface)or outside (epicardial surface) of the heart. In yet another embodiment,the electrode is configured to be part of a mitral valve device, or maybe incorporated into any valve repair or replacement device, whetherplaced by conventional open heart surgery or by an endovasculartechnique.

A beneficial feature is that these embodiments allow the electrodes andwires to be held fast against the heart tissue, which like mitraldevices commercially available, avoid thrombus formation on theelectrodes and wires. The described devices then allow sensing, pacingand/or defibrillation of the left side of the heart that has not beenclinically addressed before. For instance, these devices could be usedto directly pace the left atrium. Traditionally, only the right atriumcan be accessed for pacing. In many patients, because of intrinsicconduction issues or distension of the atria, the right atrial pacing isnot always in synch with the left atrium. With the new device in theintratribal septum, the left atrium or about the left atrium—in clinicalpractice both atria can be paced. This could allow for synchronousbi-atrial pacing, which improves the efficacy of atrial pacing and wouldimprove cardiac output and ejection fraction in some patients

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of various examples, reference will now bemade to the accompanying drawings in which:

FIG. 1 illustrates a septal electrode attached to the atrial septum, andits extensions which keep the wires against the heart tissue.

FIGS. 2A-2H illustrate a sequence of steps to attach the septalelectrode during a surgical procedure.

FIG. 3A shows a dose-up view of one example of the septal electrodewhich includes protrusions to help hold the septal electrode in placeagainst the septum.

FIG. 3B shows another example of a septal electrode with extensionfurther into the left atrium, again with the wires and electrode flushagainst the endocardium.

FIG. 3C shows yet another example of a septal electrode with deployablewings held in place by the device against the atrial wall.

FIG. 4A shows an example of an implantable medical device with a septalelectrode on one lead and another electrode on a second lead into theright ventricle.

FIG. 4B shows an example of an implantable medical device with a septalelectrode on one lead, and two additional leads anchored into the rightatrium and right ventricle.

FIG. 5 illustrates another embodiment in which an electrode is part ofan atrial appendage closure device in which the closure device isexternal to the atrial appendage, which keeps the wire of the devicetight against the atrial wall.

FIGS. 6A-6D illustrate a medical procedure for implanting the closuredevice and associated electrode of FIG. 5 .

FIG. 7 shows a close-up view of one example of the electrode configuredto be coupled to the atrial appendage closure device of FIG. 5 .

FIGS. 8A-8D illustrate another embodiment in which an electrode is partof an atrial appendage closure device in which the closure device isinternal to the atrial appendage.

FIG. 9 shows an embodiment in which an electrode is part of a mitralvalve device in which the wires are connected to the electrodes on themitral annulus and hug the atrial septum, and connect to the electrodeembedded in the septum.

DETAILED DESCRIPTION

Low profile restraining devices are described herein which eliminate theproblem of current intracardiac leads which generally are permitted tofree float within the interior volume of the corresponding cardiacchamber. The described embodiments include a mechanism that keep aportion of the lead fixed against the endocardium of the left atrium,where the electrode and lead will become embedded against the wall ofthe heart. Thus, thrombus is avoided with the described low-profiledevices on the left side of the heart. Placement of the leads, withthese devices, on the left side of the heart facilitates new therapiesfor the treatment of cardiac disease. The restraint mechanisms describedherein can be extended to other chambers of the heart.

Beneficially, the described examples are directed to leads connected tothe left atrium. For atrial arrhythmias (arrhythmias in the upperchambers of the heart), left atrial leads is a better way to sense AFand selectively defibrillate the upper chambers. A much lower energy canbe used (1-10 joules) compared to defibrillating the entire heart.Accordingly, the patient experiences much less discomfort and batterylife is increased. Leads in the LA can also provide a record of wherethe AF is initiating, which could guide further treatment to eliminatethe focus. A left atrial lead requires careful design to avoid thrombusand embolism. The embodiments described herein pertain to a deviceplaced entirely by a minimally invasive route. The device is low profileand sits flat against the endocardial wall and becomes strongly embeddedin tissue. The low nature of the device avoids or reduces the risk ofthrombus formation. The described device provides a solution for sensingand treating AF and other supraventricular arrhythmias, with lowerpower, and with shocks that are less painful to the patient.

The embodiments described herein pertain to an implantable device thatis connected to wires that contain nitinol or other types of shapememory metal that creates some torsion that keeps the wires against thewalls of the heart and prevents free floating wires. These devices canbe placed in or around the left atrium of the heart, as well as on theright side of the heart. The restraining device applies passive force tothe tissue by a curved wire bent to a looped state to provide a suitableamount of torsion. The devices can have protrusions to hold the devicein place and prevent slippage until tissue healing occurs. The electrodeportion of the device can be coated with materials such as gold toincrease its conductivity. Incorporated into the curved wire is anextension of conducting wire, also coated with a material to improveconduction (such as gold plating), to increase the surface area of thedevice. Beneficially, the extension will lie against the heart tissue,because of wire torsion. The device is also incorporated with insulatedwire(s) that will hug the heart wall. The insulated portion of thedevice will have an outer nitinol or other shape metal that keeps thewires out of the blood stream. As in other devices in the heart thatabut the endocardial surface, this device and its extensions and willbecome incorporated into the atrial tissue and will remain out of theflow of blood through the heart.

The devices then exit the heart, as with commercially available devices,to connect to a pacemaker, defibrillator or transducer or somecombination of the these. This allows the device to receive and transmitan electrical charge from a remote site, such as a transducer orpacemaker. The transducer and pacemaker devices are available fromseveral manufacturers, such as Medtronic and St. Jude Medical. Thedevice sits flat against the atrial septal wall and becomes stronglyembedded in tissue. This low profile discourages thrombus formation, andtherefore allows the devices to be placed on the left side of the heart.In clinical practice, the devices with the extensions can be used on theright side of the heart also. The device has excellent electricalcontact. The restraining device is held passively against the atrialseptum. The unique property of the restraining device easily attachingto the atrial septum with a low profile provides a safe route fordeployment. Since the extensions and the wires are constructed with ashaped memory metal or other material that holds the extensions andwires against the endocardium, the device can be deployed on the leftside of the heart.

Currently transseptal punctures are commonplace duringelectrophysiologic (EP) studies. The wires for deployment of the device,such as a transseptal sheath and guidewire and obturator are alreadyideally situated during the transseptal puncture, which is utilized toenter the left atrium. Usually these EP studies are for the treatment ofAF, so it would be straight-forward to place the restraining deviceduring an EP procedure. Prior ways to achieve good electrical contactinside the heart include screws, barbs, hooks, pins and electrodeplates. All these can be incorporated into the distal restraining deviceand to the extensions and special wires to help hold the devices againstthe heart wall. This also ensures good electrical contact. The devicecan incorporate coatings such as steroids to prevent fibrosis, lowcontact or high energy. The device can include a bioabsorbablecomponent, such that after the electrode becomes embedded in tissue, theremaining restraining portion of the device reabsorbs. The device mayalso contain an antithrombotic coating, which helps prevent thrombusformation until the device is surrounded by tissue ingrowth. The deviceis carefully designed to be low profile, but with enough strength in thedeployed position to provide complete stability in the intra-atrialseptum.

The restraining device can be integrated into any other device placed inor around the left or right atrium. The restraining device can bemodified to work with any device that is to be placed in or around theright or left atrium, including, but not limited to atrial septalclosure devices, left atrial closure devices (both intra andextracardiac) and valve repair or replacement devices. In the case of aseptal occlusion device, the restraining device is modified to beincorporated into the rings of the septal closure device. Severalpossible iterations include three electrode conducting rings around theareas of the septal device that abut the endocardium of the septum. Theexact configuration of the wire array can be changed depending on thedevice configuration, the surface area in contact, and the resistancegenerated. In the case of a mitral valve replacement, the retrainingdevice can be modified to fit in a groove where the valve device abutsatrial tissue. The wire electrodes of the device may be circular or maybe cross-hatched, or other configuration to provide the therapeuticallysufficient electrical output at the lowest energy with a suitableresistance profile.

The retraining device could be delivered together with the valve orseparately. The distal end of the lead can be affixed to, for example,the atrial septum, in or around the left atrial appendage, or in amitral valve device. This allows for low energy defibrillation of theatria in response to atrial fibrillation or other atrial arrhythmias.The device can also be used to sense electrical activity on theendocardial surface. It can be used in conjunction with other leads andwires in both atria of the heart, or left atria and either rightventricle, left ventricle or coronary sinus that can be used todefibrillate the atria. It can be used in conjunction with electrodes onthe outside of the heart as well, such as epicardial leads andelectrodes. A lead placed inside the atria can facilitate defibrillationusing a relatively low energy (1-10 Joules, J) waveform to reliablydefibrillate or pace the atria.

The lead and accompanying extensions and wires can be placed into thepatient via blood vessels in the groin or neck area. The distal regionof the lead has electrodes and is placed in or around the left atrium(e.g., atrial septum, in or around the left atrial appendage, or in amitral valve device). The wire configuration keeps the wires against theheart walls. The proximal end of the wire can be connected to a smalldefibrillator unit or a transducer that is placed subcutaneously in thepatient. Such pacemakers and defibrillators can sense, pace anddefibrillate. Because of the novel placement of the device, the upperchambers of the heart, the atria, can be selectively defibrillated,allowing for a very low energy defibrillation. The device also allowsfor sensing directly in the left atrium, which could be used to detectthe origin of arrhythmias and could be used to selectively pace the leftatrium. If a transducer is used, power can be transferred to thetransducer transcutaneously from an external device.

In one embodiment and as noted above, a restraining device is used tohold the left atrial wire in place against the atrial septum. Arestraining device is a passive mechanical device that allows atrialdefibrillation of both atria. Two devices are illustrated in FIGS. 1-4B.One is a device that has a spring effect to provide adequate restrainingforce to hold the wire in place against the septum, but without damagingthe septum. This device can have protrusions to help hold the device inplace and prevent slippage until healing occurs. This device can haveextensions to provide for additional surface area for optimal sensing,pacing, and defibrillation. The extensions contain memory shaped metalor other similar substance to provide torsion, which keeps theextensions against the walls of the heart and out of the flow of bloodthrough the heart. The second device is an array that attaches to orreplaces an atrial septal defect closure device. Both can be placed inthe patient at the end of a medical procedure such as a catheterablation procedure to treat atrial fibrillation, or as a stand-aloneprocedure. Through a combined groin and subclavian approach (the leftsubclavian approach is illustrated), the wires placed from the groin canbe brought to the subcutaneous position in the subclavian area, and thenthe defibrillator device can be placed.

FIG. 1 depicts an arrangement of the leads with one cardiac atrial lead101 placed in the right atrium (similar to the atrial lead of a dualchamber pacing configuration). Part of this embodiment is the placementof a second cardiac atrial lead 103 (the device) in the left atrium,which allows for specific atrial sensing, pacing, and/or defibrillation,with a very small amount of energy (approximately 1-10 joules). Thedistal end of the left atrial lead 103 includes a shape memory structurethat is configured to hold a portion of the lead 103 against a person'sendocardium. The shape memory structure in this example is configured tobe restrained to opposites sides of the atrial septum.

FIG. 1 also shows an electronics enclosure 110 which comprises a sealedenclosure containing a battery and a circuit. In one example, thecircuit can generate the stimulation energy to electrodes at the distalregion of the lead(s) 101, 103 for pacing and/or for defibrillation. Thecircuit additionally or alternatively can sense and record theelectrical activity from the electrode(s). The electronics enclosuredevice 110 may be a pacemaker, a defibrillator, a device that both pacesand defibrillates, and/or a sensing or recording device.

FIGS. 2A-2H illustrate a step-by-step procedure for attaching the leadsto the heart. FIG. 2A depicts the initial transseptal puncture with amodified Seldinger technique. A guidewire 201 has been inserted via, forexample, the groin and, through an obturator 202, into the left atrium.FIG. 2B depicts placing a transseptal sheath 203 through the transseptalpuncture site 205 of the atrial septum 250. FIG. 2C depicts that theobturator 202 has been removed, and the transseptal sheath 203 remainsin place with initial delivery of an anchor delivery sheath 206. Theguidewire 201 has been removed. FIG. 2D depicts a septal electrode 230(carrier or assembly) at the end of lead 103 exposed in the left atrium.The obturator 202 has been removed. FIG. 2E depicts the anchor deliverysheath 206 being retracted thereby exposing the septal electrode 230.The septal electrode 230 comprises a flexible elongate electrode. As canbe seen, the distal region of the septal electrode 230 has a naturalangled bend (approximately a right-angle bend) to it as shown.

FIG. 2F depicts the further retraction of the anchor delivery sheath 206and exposure of the septal electrode 230 against the atrial septum. Theseptal electrode 230 may comprise gold, nitinol or other suitable (e.g.,inert and biocompatible) metal to transmit electricity to the heart. Theseptal electrode 230 maintains pressure against the atrial septum whendeployed. The septal electrode 230 will maintain slight pressure on theseptum to prevent movement of the device after it is deployed. As willbe seen in the examples of FIG. 3A, the septal electrode 230 permitselectrical current to flow to the septum 250 (and beyond) from anelectronics enclosure.

FIG. 2G depicts the septal electrode 230 fully deployed against theatrial septum 250. A snare device 208 is then depicted which allows thedistal region of the lead to be moved from its insertion site (e.g., thegroin) to the subclavian area or some other chest position at which theelectronics enclosure is located. A portion 232 of the septal electrode230 in the right atrium on the opposite side of the septum 250 from theportion of the septal electrode 230 in the left atrium is bent upward asshown using the snare device 208 thereby forming a U-shaped structure asshown. Because of the mechanical properties of the device (e.g., thememory shape structure), the wires will hug the endocardial surface.

In other examples, the portion of the electrode pressed against theatrial septum in the left atrium may be longer than that shown in FIG.2G or there be an additional array attached to the lead anchor 207 toincrease the surface area along the atrial septum 250 and/or left atrium235. For example, FIG. 2H depicts an extension 235 of the septalelectrode 230 to increase the surface area for defibrillation of theleft atria 235. Again, a shape memory metal (e.g., Nitinol) coveringwill hold the extensions tight against the atrial wall. Electrode 230may be coated with a material such as gold to increase its conductivity.The curved wire can be made of nitinol or other shape memory materialthat can be straightened for implantation through a sheath into thepatient—the curve shape can form inside the patient. The memory metalwire assembly can have the memory metal or similar material on theoutside covering of the wire, as a part of the wire with insulationcovering the wire or with any combination of a steroid, heparin coatingor drug eluting coating. The device sits relatively flat against atrialwall (i.e., in continuous contact with the atrial wall such as theatrial septal wall) and eventually becomes strongly embedded in thecardiac tissue. This low profile discourages thrombus formation. Thedevice has excellent electrical contact. The restraining device is heldpassively against the atrial septum. The restraining device easilyattaching to the atrial septum with a low profile provides a safe routefor deployment.

This figure also depicts both leads 101 and 103 exiting in the leftsubclavian area or other site on the chest. An electrode 251 is shown atthe distal end of lead 101 and anchored into the right atrium 237.

FIGS. 3A-3C depict examples of devices that specifically allow foratrial defibrillation with two electrodes. One of the electrodes isplaced in the right atrium (e.g., electrode 251 shown in FIG. 2H), butother locations are possible as well such as the right ventricle, leftventricle, or coronary sinus. The other electrode comprises the septalelectrode 230 that sits along the atrial septum. FIG. 3A depicts aseptal electrode 230 hugging both sides of the atrial septum 250.Protrusions 255 (e.g., teeth) extend towards and slightly into theseptum 250 and allow secure positioning along the septal wall to helpanchor the septal electrode 230 in place on opposite sides of the septum250.

FIG. 3B is similar to FIG. 2H and depicts a septal electrode 330 huggingthe atrial septum with a left atrial (could also be right) extension 335for additional surface area (compared to septal electrode 230 in FIG.3A) for defibrillation. Protrusions 255 may be included in thisembodiment as well to help hold septal electrode 330 and its extension335 in place.

FIG. 3C depicts an alternate septal electrode 400 which covers bothsides of the atrial septum 250. Septal electrode 400 comprises a plughaving an electrode array The plug can have electrode properties, or theplug may incorporate electrode(s) with sufficient conductivity, such asgold plating. The extra electrode(s) can be weaved into the plug, or canbe a circular electrode on one or both sides of the device, or can bemore than one electrode in circles about the circumference or radius orin between the plug. The extra electrode is attached to a wire 410 whichexits the heart in the same manner as the device in FIGS. 3A and 3B.Opposing wings 420 and 430 can be deployed (e.g., fan out) to anchor thedevice against the septum 250 as shown.

FIG. 4A shows an atrial defibrillator (or pacemaker, sensor, orrecording device) implanted in a person with the septal electrode 230 oflead 103 connected to a battery-powered electronics enclosure 450(similar to electronics enclosure 110 described above) and attached tothe atrial septum and another lead 510 provided into and anchored to theright ventricle. The electronics enclosure comprises a sealed enclosure,a battery contained therein, and a circuit to generate electricalstimulation signals to be provided to the electrodes at the distal endsof the leads. FIG. 4B shows the atrial defibrillator implanted in aperson with the septal electrode 230 of lead 103 attached to the atrialseptum, a second lead 510 provided into and anchored to the rightventricle, and a third lead 511 anchored into the right atrium.

FIGS. 5-7 illustrate an embodiment in which an atrial electrode isincluded in a device that occludes an orifice of the atrial appendagefrom outside the heart. FIG. 5 depicts an arrangement of the leads of adefibrillator with one atrial lead 101 placed in the right atrium 237. Asecond atrial lead 510 is placed in or about the atrial appendage 520 ofthe left atrium 235 and is attached to an atrial appendage closuredevice that is used to close the orifice between the left atrium 235 andthe atrial appendage 520. The leads 101 And 510 and their electrodesallow for specific atrial defibrillation of the atria, with a very smallamount of energy (approximately 1-10 joules). The device extensionscontain memory shaped metal or another composition, such as plastic,which holds the extensions tight against outside of the left atrium.FIG. 5 also shows the pulse generator 450 which comprises a sealedenclosure containing a battery and a circuit to generate the stimulationenergy to electrodes at the distal end of the lead(s) 101 and 510.

FIG. 6A shows a portion of the procedure to implant an atrial appendageclosure device around the atrial appendage 520. Installation of theatrial appendage closure device includes a magnet 525 positioned via asheath 521 inside the atrial appendage 520. A second magnet 535 isbrought near magnet 525 from outside the heart via a sheath 540 insertedthrough a small incision in the patients chest. The orifice 521 is shownbetween the left atrium 235 and the atrial appendage 520. Once themagnet 535 is brought close enough to magnet 525, the magneticattraction causes the two magnets into contact with the wall of theatrial appendage 520 sandwiched therebetween. The magnets stabilize theatrial appendage 520. FIG. 6A also shows the distal end of a sheath 545containing a lariat (discussed below).

FIG. 6B depicts the deployment of a lariat 550 around the base of theatrial appendage 520. The lariat 550 may be made of suture material orwire. FIG. 6C depicts a lead extension with electrodes 560 and 565attached to the lariat 550. The electrodes can be placed on the lariatdevice before insertion into the body. The electrode array may varydepending on which configuration provides the optimal delivery of joulesat the lowest resistance. There can be one or more electrodes fixed tothe lariat. The electrodes may be longer and unfurl against the outsideof the LA upon deployment. The covering or composition of the extensionscontain memory shaped metal or other material that ensures theextensions remain in contact with the left atrium, or other epicardialsurfaces. The specific length and number of electrodes and whether theyunfurl depends on the energy needed to deliver the appropriate energyfor defibrillation and the acceptable resistance generated. FIG. 6Dshows the lariat 550 in place and cinched around the base of the of theatrial appendage 520 thereby closing off the orifice from the leftatrium 525 into the atrial appendage. FIG. 6D also shows the electrode560 positioned on the lariat 550 and thus just outside the left atrium.

FIG. 7 depicts the electrode 560 separate from the lariat 550. In thisexample, the electrode 550 is a coiled spring electrode. The electrodemay unfurl and be present on the outside of the LAA base and or LA.There can be more than one electrode. The configuration can be a star orcircle or other shape. However, the configuration of the electrode 560may be other than that shown in FIG. 7 in other embodiments. In otherexamples, the portion of the electrode pressed against the left atrialtissue may be longer than that shown in FIG. 7 or there may be one ormore additional electrodes on the lariat 550 to increase the surfacearea along the left atrium. The configuration of the electrode array mayvary somewhat also to accommodate the size of the atrial appendageclosure device.

FIGS. 8A-8D illustrate the closure of the orifice between the leftatrium 235 and the atrial appendage 520 from inside the heart using aplug 810 (also referred to as a left atrial appendage occluder). Theplug 810 is fitted with one or more electrodes connected to a pulsegenerator (e.g. pulse generator 450) and used for defibrillation. One ormore other electrodes are positioned in the right atrium, rightventricle, left ventricle, coronary sinus, or intra-atrial septum. Theplug 810 is deployed through a sheath 805.

FIG. 8B shows the retraction of the sheath 805 and a plug deploymentmember 807. A lead 820 is shown inside the plug deployment member 807.The lead 820 is exposed when the sheath 805 and plug deployment member807 are retracted. Electrodes 830 are shown on the lead 820 inside theatrial appendage 520. The device keeps the wires snugly against theinside heart walls, which keep the wires out of the flow of blood. Inthis position, the wires become embedded in the atrial wall.

In FIG. 8C, the lead 820 from the left atrial closure device (plug 810)extends from the device and upon retraction of the sheath 805 and plugdeployment member 807 brings the attached lead 820 into the right atrium237. In the right atrium 237, the lead is then grasped or directed witha snare device 208 to be delivered into the left or right subclavianvein or other vein for connection to a pulse generator 450 that would beplaced subcutaneously as described above. FIG. 8C also shows a lattice812 coupled to a U-shaped dip 811 that is coupled to the septum 250. Thelattice includes, for example, a first wire 812 and a second wire 813,both coupled to the U-shaped clip 811 and configured to be restrainedagainst the endocardium of the left atrium 235. More than two wires canbe included as desired. The wires 812 and 813 are interconnected andspaced apart by one or more interconnecting wires 815, also which arerestrained against the wall of the left atrium. The U-shaped dip 811 andwires 813, 814, and 815 may be formed from any suitable type of shapememory metal, such as Nitinol.

FIG. 8D shows the final configuration of plug 810 closing off the atrialappendage 520 with the left atrial lead 820 extending from the leftatrial closure device (plug 810), extending along and hugging theinterior wall of the left atrium 235. The wire then traverses the atrialseptum to the right atrium. The lead 820 then extends through thesuperior vena cava (alternatively, the inferior vena cava) to a moreperipheral vein that would allow access to the pulse generator 450(which may be configured to perform defibrillation and/or pacing). Aright atrial (as in FIG. 1 , lead 101) may also be present and connectedto the pulse generator 450. Such additional lead could also be a leadpositioned in, for example, the right ventricle, left ventricle, orcoronary sinus lead.

In the example of FIGS. 8C and 8D, the active electrode (providingstimulation or sensing capability) can be provided on the lattice 812(e.g., wire 814), in or on the plug 810, or on both the lattice and theplug. In one embodiment, the electrode is on one of wires 813 or 814 ofthe lattice 812, and the other wire 813, 814 of the lattice with itsshape memory helps to force the electrode-carrying wire into continuouscontact with the atrial wall. In one embodiment, the lattice 812 ispresent but not the plug 810. Further, the U-shaped dip 811 may or maynot have an electrode. In one example, the dip 811 functions as ananchor for another structure (e.g., the lattice 812, a pacing lead,etc.) and is not itself used for sensing or stimulation purposes.

In another embodiment, a left atrial lead can be incorporated a mitralvalve replacement and/or mitral valve repair, either transseptal via apercutaneous approach or minimally invasive or open surgical approach.For example, an electrode array can be incorporated into mitral valvedevices that touch or are near the left atrium. FIG. 9 shows aprosthetic mitral valve device 910 which is incorporated with one ormore electrodes 920 forming an electrode array. The electrodes 920 areon the distal end of an atrial lead. The lead 930 would then be routedthrough the atrial septum 250 and connected to a pulse generator 450 asdescribed above. The orifice of the mitral valve, where most mitralvalve devices (such as mitral valve device 910) are positioned, is asuitable site for bi-atrial defibrillation with the device describedherein. One configuration of the electrode array would be a conductivethin wire woven or otherwise attached to the valve device 910 as it sitsaround the mitral orifice. The mitral valve device 910 or devices mayaccommodate the electrode array and lead 930. Lead 930 can extend andoverlap with the septal restraining device. The septal restrainingdevice then connects to an insulated wire which connects to a pacemakerand/or defibrillator or transducer. The mechanical properties of thedevice hold the wires and extensions against the atrial wall, wheretissue ingrowth will occur, as it does with the implanted mitral valve.The lead 930 can also allow attachment to another grasping device (e.g.,snare device 208) to bring the wire to the appropriate site near thedefibrillator/pacemaker pocket.

Some embodiments are directed to a support structure for a pacemakerlead. The support structure is coupled to the pacemaker lead and isconfigured to restrain a portion of the pacemaker lead against aperson's atrial wall. Examples of the support structure are describedherein and include, for example, a U-shaped clip, a lattice, etc. thesupport structure may comprise a shape memory material (e.g., Nitinol).

Using the structures described herein, a method for implanting a lead inthe left side of a heart can comprise introducing the lead into a bloodvessel, advancing the lead into a left atrium, fixing a distal region ofthe lead in position flush against the atrial septum with anchorelements on both sides of the atrial septum, and affixing an electrodeon the lead in contact with the endocardium of the heart. Further,advancing the lead into the left atrium may include advancing theelectrode beyond the septum and into continuous contact with the atrialwall. A lattice may be positioned in the left atrium to maintain thedistal region of the lead in contact with the atrial wall.

Modifications are possible in the described embodiments, and otherembodiments are possible, within the scope of the claims.

What is claimed is:
 1. An implantable medical device, comprising: acardiac lead having a distal region and a proximal end, the proximal endof the cardiac lead adapted to be coupled to an electronics enclosure,the distal region of the cardiac lead having a structure configured tohold a portion of the distal region of the lead against a person'sendocardium, the structure configured to attach to opposite sides of anatrial septum; wherein the distal region of the lead also has anelectrode configured to be attached to the person's endocardium.
 2. Theimplantable medical device of claim 1, wherein the structure comprises aseptal closure device.
 3. The implantable medical device of claim 1,wherein the structure comprises a shape memory material.
 4. Theimplantable medical device of claim 1, wherein the structure includesprotrusions configured to mate to the endocardium.
 5. The implantablemedical device of claim 1, wherein the structure includes a U-shapeddip.
 6. The implantable medical device of claim 5, wherein the electrodeis on the U-shaped dip.
 7. The implantable medical device of claim 1,wherein the distal region includes a wire extension coupled to thestructure and configured to be restrained against the person'sendocardium.
 8. The implantable medical device of claim 7, wherein theelectrode is on the wire extension.
 9. The implantable medical device ofclaim 1, wherein the structure comprises a lattice.
 10. The implantablemedical device of claim 9, wherein the lattice is configured to restrainthe distal region of the cardiac lead to the person's endocardium. 11.The implantable medical device of claim 9, wherein the electrode is onthe lattice.
 12. The implantable medical device of claim 9, furtherincluding a U-shaped dip configured to attach to a septum of the person,and wherein the lattice comprises: a first wire coupled to the U-shapeddip and configured to be restrained against the person's endocardium; asecond wire also coupled to the U-shaped dip and configured to berestrained against the person's endocardium; an interconnecting wireconnected to the first and second wires to space apart the first andsecond while restrained against the person's endocardium.
 13. Theimplantable medical device of claim 1, further including a mitral valvedevice, and the electrode is part of the mitral valve device.
 14. Theimplantable medical device of claim 13, wherein: the shape memorystructure includes a U-shaped dip configured to be attached to theperson's septum; and the electrode is coupled to the U-shaped dip by wayof a shape memory wire that is configured to be restrained against theperson's endocardium between the mitral valve device and the U-shapeddip.
 15. An implantable medical device, comprising: a pacemaker leadhaving a distal end and a proximal end, the proximal end of the cardiaclead adapted to be coupled to an electronics enclosure, the distal endof the pacemaker lead having an electrode; and a support structurecoupled to the pacemaker lead and configured to restrain a portion ofthe pacemaker lead against a person's atrial wall.
 16. The implantablemedical device of claim 15, wherein the support structure is a lattice.17. The implantable medical device of claim 15, wherein the supportstructure comprises a U-shaped clip.
 18. The implantable medical deviceof claim 15, wherein the support structure comprises a shape memorymaterial.
 19. A method for implanting a lead in the left side of aheart, comprising: introducing the lead into a blood vessel; advancingthe lead into a left atrium; fixing a distal region of the lead inposition flush against the atrial septum with anchor elements on bothsides of the atrial septum; and affixing an electrode on the lead incontact with the endocardium of the heart.
 20. The method of claim 19,wherein advancing the lead into the left atrium comprises advancing theelectrode beyond the septum and into continuous contact with the atrialwall.
 21. The method of claim 19, further including positioning alattice in the left atrium to maintain the distal region of the lead incontact with the atrial wall.